I am going to buy a fish finder but not sure what to get. This is where you folks come in. When I look at fish finders I see some with 4000 watts, some down to 800. If I am fishing only in inland lakes that only go down to maybe 200 ft. does it matter how much power these units have? I see units that have 240 pixels and some with 480 vertical pixels. Would 320 be plenty? Am wanting to spend around $200.00 maybe a little more or a little less for a good unit. Am looking at Garmin, Eagle and Bottom Line. Please tell me what you think.